Tensile Property and Corrosion Performance of Ag Microalloying of Al-Cu Alloys for Positive Electrode Current Collectors of Li-Ion Batteries

Abstract

The development of a current collector for Li-ion batteries is of great significance for improving the performance of Li-ion batteries. Tensile property and corrosion performance of the positive electrode current collectors are an indispensable prerequisite for the realization of high-performance Li-ion batteries. In our study, the effects of Ag alloying on the microscopic structure, electrical conductivity, tensile property and corrosion resistance of Al-xCu (x = 0.1–0.15%) alloy foils were investigated. Moderate Ag addition on the Al-Cu alloy could reduce the size of second phases and promote the formation of second phases. The tensile strength of the Al-0.1Cu-0.1Ag alloy was higher than that of the Al-0.1Cu alloy at both room and high temperatures. All of the alloy foils demonstrated high electrical conductivity around 58% ICAS. The corrosion potential and corrosion current density of the Al-0.1Cu alloy were demonstrated by Tafel polarization to be −873 mV and 37.12 μA/cm2, respectively. However, the Al-0.1Cu-0.1Ag alloy showed enhanced corrosion resistance after the Ag element was added to the Al-0.1Cu alloy, and the Al-0.1Cu-0.1Ag alloy had a greater positive corrosion potential of −721 mV and a lower corrosion current density of 1.52 μA/cm2, which suggests that the Ag element could significantly improve the corrosion resistance of the Al-Cu alloy.